Apparatus for mapping includes a radiation source, which is configured to emit a beam of radiation, and a detector and optics, which define a sensing area of the detector. A scanning mirror assembly is configured to receive and scan the emitted beam over a selected angular range within a region of interest while scanning the sensing area over the selected angular range in synchronization with the scanned beam from the radiation source. A processor is configured to process signals output by the detector in order to construct a three-dimensional (3D) map of an object in the region of interest.
|
8. A method for mapping, comprising:
using a scanning mirror assembly, scanning a beam of radiation over a selected angular range within a region of interest while scanning a sensing area of a detector, using the scanning mirror assembly, over the selected angular range in synchronization with the scanned beam; and
processing signals output by the detector in order to construct a three-dimensional (3D) map of an object in the region of interest.
1. Apparatus for mapping, comprising:
a radiation source, which is configured to emit a beam of radiation;
a detector and optics, which define a sensing area of the detector;
a scanning mirror assembly, which is configured to receive and scan the emitted beam over a selected angular range within a region of interest while scanning the sensing area over the selected angular range in synchronization with the scanned beam from the radiation source; and
a processor, which is configured to process signals output by the detector in order to construct a three-dimensional (3D) map of an object in the region of interest.
16. Apparatus for mapping, comprising:
an illumination module, comprising:
a first radiation source, which is configured to emit a beam of infrared radiation;
a second radiation source, which is configured to emit a visible light beam; and
a scanner, which is configured to receive and scan both the infrared beam and the visible light beam simultaneously over a selected angular range onto a region of interest;
a detector, which is configured to receive the infrared radiation that is reflected from an object in the region of interest; and
a processor, which is configured to process signals output by the detector in order to construct a three-dimensional (3D) map of the object, while modulating the visible light beam so as to project a visible image onto the region of interest.
2. The apparatus according to
3. The apparatus according to
4. The apparatus according to
5. The apparatus according to
6. The apparatus according to
7. The apparatus according to
a first radiation source, which emits an infrared beam, which is received by the detector in order to output the signals; and
a second radiation source, which emits a visible light beam, which is modulated to project a visible image onto the region of interest,
wherein the scanning mirror assembly is configured to project both the infrared beam and the visible light beam onto the region of interest simultaneously.
9. The method according to
10. The method according to
11. The method according to
12. The method according to
13. The method according to
14. The method according to
15. The method according to
17. The apparatus according to
18. The apparatus according to
19. The apparatus according to
20. The apparatus according to
|
This application is a continuation of U.S. patent application Ser. No. 14/749,654, filed Jun. 25, 2015, which is a continuation of U.S. patent application Ser. No. 13/810,451 (now U.S. Pat. No. 9,098,931), filed Jan. 16, 2013, in the national phase of PCT Patent Application PCT/IB2011/053560, filed Aug. 10, 2011, which claims the benefit of U.S. Provisional Patent Application 61/372,729, filed Aug. 11, 2010, and U.S. Provisional Patent Application 61/425,788, filed Dec. 22, 2010. All of these related applications are incorporated herein by reference.
The present invention relates generally to methods and devices for projection and capture of optical radiation, and particularly to projection and image capture for purposes of 3D mapping.
Various methods are known in the art for optical 3D mapping, i.e., generating a 3D profile of the surface of an object by processing an optical image of the object. This sort of 3D profile is also referred to as a 3D map, depth map or depth image, and 3D mapping is also referred to as depth mapping.
Some methods of 3D mapping are based on projecting a laser speckle pattern onto the object, and then analyzing an image of the pattern on the object. For example, PCT International Publication WO 2007/043036, whose disclosure is incorporated herein by reference, describes a system and method for object reconstruction in which a coherent light source and a generator of a random speckle pattern project onto the object a coherent random speckle pattern. An imaging unit detects the light response of the illuminated region and generates image data. Shifts of the pattern in the image of the object relative to a reference image of the pattern are used in real-time reconstruction of a 3D map of the object. Further methods for 3D mapping using speckle patterns are described, for example, in PCT International Publication WO 2007/105205, whose disclosure is also incorporated herein by reference.
Other methods of optical 3D mapping project different sorts of patterns onto the object to be mapped. For example, PCT International Publication WO 2008/120217, whose disclosure is incorporated herein by reference, describes an illumination assembly for 3D mapping that includes a single transparency containing a fixed pattern of spots. A light source transilluminates the transparency with optical radiation so as to project the pattern onto an object. An image capture assembly captures an image of the pattern on the object, and the image is processed so as to reconstruct a 3D map of the object.
The embodiments of the present invention that are described hereinbelow provide methods and apparatus for efficient projection of patterns, particularly for 3D mapping, as well as for imaging of such projected patterns.
There is therefore provided, in accordance with an embodiment of the present invention, apparatus for mapping, which include an illumination module, including a radiation source, which is configured to emit a beam of radiation, and a scanner, which is configured to receive and scan the beam over a selected angular range. Illumination optics are configured to project the scanned beam so as to create a pattern of spots extending over a region of interest. An imaging module is configured to capture an image of the pattern that is projected onto an object in the region of interest. A processor is configured to process the image in order to construct a three-dimensional (3D) map of the object.
The pattern of the spots may be uncorrelated over a range of depths that is mapped by the apparatus.
In some embodiments, the radiation source is controlled so as to modulate an intensity of the beam while the scanner scans the beam, thereby creating the pattern of the spots on the region of interest. The illumination module may be configured to modify the pattern responsively to the image captured by the imaging module. The illumination module may be configured to control at least one of the radiation source and the scanner so as to modify an angular density of the spots in the array within a selected part of the region of interest. Alternatively or additionally, the illumination module may be configured to control at least one of the radiation source and the scanner so as to modify a brightness of the spots in a selected area with the region of interest.
In an alternative embodiment, the scanner is configured to scan the beam over a first angular range, and the optics include a beamsplitter, which is configured to create multiple, angularly-spaced replicas of the scanned beam, which together extend over a second angular range, which is greater than the first angular range. The scanner and the beamsplitter may be configured to tile the region of interest with the pattern created by the multiple, angularly-spaced replicas of the scanned beam.
In another embodiment, the optics include a patterned element, which is configured, when illuminated by the beam, to create the pattern over a first angular range, and the scanner is configured to direct the beam to strike the patterned element at multiple different angles in succession so as to create multiple, angularly-spaced replicas of the pattern, which together extend over a second angular range, which is greater than the first angular range. The scanner and the patterned element may be configured to tile the region of interest with the multiple, angularly-spaced replicas of the pattern.
In still another embodiment, the scanner is configured to scan the beam over a first angular range, and the optics include a scan-expanding element, which is configured to distribute the scanned beam so as to cover a second angular range, greater than the first angular range, with the spatial pattern. The scan-expanding element may be selected from a group of elements consisting of a convex reflector and a diffractive optical element.
In a disclosed embodiment, the illumination module includes at least one beam sensor, which is positioned at a selected angle within the angular range that is scanned by the scanner so as to receive the scanned beam periodically and verify thereby that the scanner is operating. Typically, the illumination module is configured to inhibit emission of the beam from the radiation source when the sensor fails to receive the scanned beam periodically.
In some embodiments, the radiation source includes a first radiation source, which emits an infrared beam, which is modulated to create the pattern of the spots, and a second radiation source, which emits a visible light beam, which is modulated to project a visible image onto the region of interest. The scanner and optics are configured to project both the infrared beam and the visible light beam onto the region of interest simultaneously. Typically, the second radiation source is controlled so as to project the visible image onto the object responsively to the 3D map.
In disclosed embodiments, the processor is arranged to derive the 3D map by finding respective offsets between the spots in areas of the captured image and corresponding reference spot locations belonging to a reference image of the pattern, wherein the respective offsets are indicative of respective distances between the areas and the image capture assembly. In some embodiments, the imaging module includes a position-sensitive detector, which is configured to sense and output an offset of each spot in the pattern on the object as the spot is projected by the illumination module. The imaging module may be configured to scan a field of view of the position-sensitive detector in synchronization with the scanner in the illumination module or together with the beam from the radiation source.
Alternatively or additionally, the illumination module and the imaging module are arranged so that the offsets occur in a first direction, and the imaging module includes an array of detector elements arranged in one or more rows extending in the first direction, and astigmatic optics, which are configured to image the pattern onto the array and have a greater optical power in the first direction than in a second, perpendicular direction.
In some embodiments, the imaging module includes a sensor and imaging optics, which define a sensing area that is scanned over the region of interest in synchronization with the scanned beam of the illumination module. The sensor may include an image sensor having a rolling shutter, wherein the rolling shutter is synchronized with the scanned beam. Additionally or alternatively, the scanner in the illumination module may be controllable to dynamically vary the selected angular range, and the imaging module may include an imaging scanner, which is configured to dynamically scan the sensing area to match the selected angular range of the scanned beam.
There is also provided, in accordance with an embodiment of the present invention, apparatus for mapping, which includes an illumination module, including a radiation source, which is configured to emit a beam of radiation having an intensity that varies according to a specified temporal modulation. A scanner is configured to receive and scan the beam over a region of interest, so as to project the radiation onto the region with a spatial intensity pattern determined by the temporal modulation of the beam. An imaging module is configured to capture an image of the spatial intensity pattern that is projected onto an object in the region of interest. A processor is configured to process the image in order to construct a three-dimensional (3D) map of the object.
In a disclosed embodiment, the temporal modulation is binary, and wherein the spatial intensity pattern includes an array of spots generated by the temporal modulation.
In one embodiment, the imaging module includes a sensor and imaging optics, which define a sensing area that is scanned over the region of interest in synchronization with the scanned beam of the illumination module.
There is additionally provided, in accordance with an embodiment of the present invention, a method for mapping, which includes scanning a beam of radiation over a selected angular range so as to create a pattern of spots extending over a region of interest. An image of the pattern that is projected onto an object in the region of interest is captured and processed in order to construct a three-dimensional (3D) map of the object.
There is further provided, in accordance with an embodiment of the present invention, a method for mapping, which includes generating a beam of radiation having an intensity that varies according to a specified temporal modulation. The beam is scanned over a region of interest, so as to project the radiation onto the region with a spatial intensity pattern determined by the temporal modulation of the beam. An image of the spatial intensity pattern that is projected onto an object in the region of interest is captured and processed in order to construct a three-dimensional (3D) map of the object.
The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which:
The embodiments of the present invention that are described hereinbelow provide, inter alia, methods and apparatus for efficient projection of patterns, particularly for 3D mapping, as well as for efficient imaging of such projected patterns.
In some embodiments of the present invention, an illumination module projects a pattern of spots onto a region of interest, and an imaging module captures an image of the pattern appearing on objects in the region. This image is processed in order to find the locations of the spots in the image and, on this basis, to construct a 3D map of an object in the region of interest. The depth coordinates in the map are computed by triangulation, typically based on the offsets of the spots in the image relative to corresponding reference spot locations in a reference image of the pattern.
In the disclosed embodiments, the pattern is projected dynamically, i.e., it is not projected all at once over the entire region, but is rather created by scanning a beam emitted by a radiation source. The beam is scanned over a selected angular range. (Some of the disclosed embodiments are directed to controlling and/or expanding this range.) The intensity of the beam is typically modulated during the scan in order to create the desired pattern. The scan is “dynamic” in the sense that aspects of the pattern, such as its density, brightness, and/or angular range, may be modified in the course of mapping a given scene. Although the embodiments described hereinbelow are drawn specifically to spot patterns, the principles of the present invention may similarly be applied in creating patterns of other sorts for purposes of 3D mapping.
This dynamic scanning approach is advantageous in a number of important respects. For example, dynamic scanning in this manner affords flexibility in creation of the pattern, particularly in that the pattern can be modified on the basis of the image of the region of interest. For example, the angular density of the spots in the pattern and/or the brightness of the spots can be varied in different areas, depending on scene conditions and features of objects of interest in the scene.
The imaging module can likewise be operated dynamically in conjunction with the scan of the illuminating beam, so that the active field of view of the imaging module tracks the area of the pattern that is actually illuminated at any point in the scan. The image thus created of the region of interest is not necessarily captured all at once, as in conventional image sensors, but may be assembled electronically based on local signals captured by a detector during the scan, as a part of the process of creating the 3D map. Concentrating the illumination and detection resources in a small, moving area in this way can enhance the signal/background ratio of the detected pattern and hence improve the accuracy of 3D mapping. The field of view of the imaging module can track the scan of the illuminating beam optically, possibly using (at least in part) the same scanner as the illumination module, or electronically, using an image sensor with a rolling shutter, for example.
Some of the embodiments described below are directed to expanding the angular range of the scan provided by the illumination module. These embodiments address the need of some 3D mapping systems for a wide field of view, which is much larger than the scan range of some conventional scanners. In one such embodiment, the optics of the projection module comprise a beamsplitter, which simultaneously creates multiple, angularly-spaced replicas of the scanned beam. These replicas together extend over a larger angular range than the scan range. In another embodiment, the scanner directs the beam from the radiation source to strike a patterned element at multiple different angles in succession, and thus to create multiple, angularly-spaced replicas of the pattern. In either case, the elements of the illumination module may be configured to tile the region of interest with the pattern in this manner, i.e., to cover the region with adjacent replicas of the pattern, without significant overlap or gaps between the replicas. (In this context, gaps or overlaps are considered “significant” if they are on the order of the spacing between the spots or larger than this order.)
Alternatively or additionally, the illumination module may comprise a scan-expanding element, such as a convex reflector or a diffractive optical element (DOE), which expands the angular range covered by the scanned beam.
Other applications of and variations on the elements of a 3D mapping system using a scanned radiation source are described hereinbelow.
In the example shown in
A processor 46 in device 22 processes the shift values (after computing the shift values from the raw pixel values output by module 38 if necessary) in order to generate a depth map of the region of interest that is illuminated and imaged by device 22. The depth map comprises an array of 3D coordinates, comprising a depth (Z) coordinate value of the object surface at each point (X,Y) within a predefined field of view. (In the context of an array of image-related data, these (X,Y) points are also referred to as pixels.) In the present embodiment, the processor computes the 3D coordinates of points on the surface of the object 28 by triangulation, based on the transverse shift of the pattern at each pixel. The principles of such triangulation computations are described, for example, in the above-mentioned PCT publications WO 2007/043036, WO 2007/105205 and WO 2008/120217.
In alternative embodiments, elements of device 22 may be used, mutatis mutandis, in other types of depth mapping systems, such as systems that are based on measurement of the time of flight of light pulses to and from the scene of interest or stereoscopic systems, as well as in other sorts of applications that use projected beams.
In
As noted above, illumination module 30 illuminates the scene of interest with a pattern of spots, such as an uncorrelated pattern of spots. In the context of the present patent application and in the claims, the term “uncorrelated pattern” refers to a projected pattern of spots (which may be bright or dark), whose positions are uncorrelated in planes transverse to the projection beam axis. The positions are uncorrelated in the sense that the auto-correlation of the pattern as a function of transverse shift is insignificant for any shift that is larger than the spot size and no greater than the maximum shift that may occur over the range of depths mapped by the system. Random, pseudo-random and quasi-periodic patterns are typically uncorrelated to the extent specified by the above definition.
To generate the pattern of spots, module 30 typically comprises a suitable radiation source 32, such as a collimated diode laser or a light-emitting diode (LED) or other light source with a radiation beam of appropriate shape. The beam is scanned over a range of angles by a suitable scanner 34 and illumination optics 35. The beam is modulated during the scan in order to generate the pattern. For example, the beam may be temporally modulated by turning source 32 on and off to create a binary pattern of spots or other forms. Optics 35 typically comprise one or more lenses and/or other optical components, which may take various different forms in different embodiments, as described below. The pattern is projected onto the scene over a certain angular range, which defines a projection field of view (FOV) 36, thus converting the temporal modulation of source 32 into a desired spatial intensity pattern extending over objects in the region of interest of system 20.
In the disclosed embodiments, scanner 34 comprises a scanning mirror 50 with a mechanical scan drive, although other types of scanners (such as acousto-optical scanners) may alternatively be used. Scanner 34 may comprise, for example, a bi-directional scanning mirror or a pair of uni-directional scanning mirrors. Such mirrors may be based on integrated micro-electromechanical systems (MEMS) technology. Scanning mirrors of this sort are produced by a number of manufacturers, such as Microvision, Inc. (Redmond, Wash.).
Imaging module 38 typically comprises objective optics 42, which form an image on a sensor 40 of the projected pattern appearing on the scene in the region of interest. In the example pictured in
As noted above, radiation source 32 typically emits IR radiation. Sensor 40 may comprise a monochrome sensor, without an IR-cutoff filter, in order to detect the image of the projected pattern with high sensitivity. To enhance the contrast of the image captured by sensor 40, optics 42 or the sensor itself may comprise a bandpass filter (not shown), which passes the wavelength of radiation source 32 while blocking ambient radiation in other bands.
Processor 46 typically comprises an embedded microprocessor, which is programmed in software (or firmware) to carry out the processing and control functions that are described herein. The processor may, for example, dynamically control illumination module 30 and/or imaging module 38 to adjust parameters such as the pattern density, brightness, and angular extent, as described in detail hereinbelow. A memory 48 may hold program code, lookup tables, and/or interim computational results. Alternatively or additionally, processor 46 may comprise programmable hardware logic circuits for carrying out some or all of its functions. Details of the implementation of a depth mapping processor, which may be applied to processor 46, are provided in U.S. Patent Application Publication 2010/0007717, whose disclosure is incorporated herein by reference.
To expand this range, a beamsplitter 55, such as a suitable diffractive optical element (DOE), splits the scanned beam to create multiple, angularly-spaced replicas 56, 58, 60 of the scanned beam. (In the absence of the beamsplitter, module 30 would project only beam 56.) As mirror 50 scans the radiation beam, replicas 56, 58, 60 sweep in parallel over the region of interest, covering an angular range that is greater than the scan range provided by the scanner alone. Although for the sake of simplicity,
In terms of optical principles, this embodiment is similar to DOE-based schemes that are described in U.S. Patent Application Publications 2009/0185274 and 2010/0284082, both of which are incorporated herein by reference. These publications describe methods for creating diffraction patterns using a pair of DOEs, one of which splits an input beam into a matrix of output beams, while the other applies a pattern to each of the output beams. The two DOEs together thus project radiation onto a region in space in multiple adjacent instances of the pattern.
In the present embodiment, the scan pattern of mirror 50 takes the place of one of the DOEs in splitting the input beam from radiation source 32 into multiple intermediate beams 72. For this purpose, mirror 50 scans in the X- and Y-directions to each of a matrix of predetermined angles and dwells at each of these angles for a certain period of time, typically on the order of a few milliseconds. Each dwell point defines a beam 72. DOE 70 diffracts each of beams 72 into a patterned output beam 74, along a respective axis 76. The fan-out angle between axes 76 and the divergence angle of beams 74 may be chosen (by appropriate design of DOE 70 and of the scan pattern of mirror 50) so that beams 74 tile field of view 36, in the manner shown in
The embodiment of
To avoid this eventuality, module 30 comprises one or more beam sensors 80, 82, . . . , such as photodiodes, which are coupled to processor 46 (not shown in this figure). These sensors are positioned at a selected angle or angles within the angular range that is scanned by mirror so as to receive the scanned beam periodically and thus verify that the scanner is operating. In this example, two sensors are shown on opposite sides of FOV 36, but a single safety sensor or a larger number of such sensors may alternatively be used.
The mechanism that drives mirror 50 may be programmed, for example, to direct the beam from source 32 toward sensor 80 at the beginning of each scan and toward sensor 82 at the end of each scan. When the beam strikes one of the sensors, that sensor outputs a pulse to processor 46. The processor monitors the pulses and tracks the time elapsed from pulse to pulse. If the time exceeds a preset maximum, the processor will immediately inhibit emission of the beam from radiation source 32 (typically by simply shutting it off). This sort of timing event will occur if mirror 50 gets stuck at a given location. Thus, in such a case, the beam from module 30 will be immediately shut off, and any potential safety hazard will be averted.
In the pictured embodiment, mirror 50 scans over an angular range equal to αmirror/2, giving an initial FOV of width αmirror, typically on the order of 10-30°. The beam from mirror 50 strikes a scan-expanding element—in this case a convex reflector 88—which expands the beam range so that FOV 36 has width αout, which may be on the order of 60-120°. For two-dimensional (X-Y) scanning, element 60 may be spherical, or it may have a surface with different radii of curvature in the X and Y directions in order to generate a field of view that is wider in one dimension than the other, or it may have some other aspheric shape. Alternatively, the scan-expanding reflector may be replaced by a DOE or a refractive element (not shown) with similar scan-expanding properties. Further alternatively, the function of reflector 88 may be fulfilled by a combination of optical elements of the same or different types.
System 90 is shown here in order to exemplify some of the difficulties that may be encountered by 3D mapping systems. Objects in the mapped scene may vary greatly in size, and frequently small objects (such as the participants' hands, legs and heads) move and change their apparent form quickly. Furthermore, it is often just these objects that need to be mapped accurately for purposes of the game running on console 92 and other interactive applications. At the same time, different objects in the region of interest may reflect the patterned illumination back to device 22 with widely-varying intensity, due both to variations in reflectance and to large differences in distance from the device. As a result, some areas of the pattern in the images captured by imaging module 38 may be too dim to give accurate depth readings.
To overcome these problems, illumination module 30 in device 22, projects the pattern adaptively, changing the density and/or brightness of the pattern in response to the geometry of the scene. The information about scene geometry is provided by the images captured by imaging module 38 and/or by the 3D maps that are generated by processing these images. Thus, radiation source 32 and scanner 34 are controlled dynamically, during operation of system 90, to project spots 100 with greater density on objects of importance that are either small or rapidly varying, or otherwise require closer attention or better depth coverage, such as the bodies of participants 94 and 96. On the other hand, large smooth objects, such as background 98, are covered with a sparser pattern. Device 22 may adjust the pattern density adaptively in successive images, in response to changes in the scene.
Additionally or alternatively, device 22 may adjust the output power of radiation source 32 dynamically, in order to compensate for variations in distance and reflectivity within the captured scene. Thus, illumination module may project spots with greater brightness toward objects that have low reflectivity or are far from device 22, such as background 98, while reducing the projected power on bright, nearby objects. Alternatively or additionally, the local scanning speed of the mirror, and thus the dwell time at each location in the scan range, may be controlled to give longer local dwell time, and hence greater local projected energy, in areas requiring greater illumination. These sorts of adaptive power control enhance the dynamic range of system 90 and optimizes the use of available radiation power.
As a further aspect of the dynamic operation of system 90 (not illustrated in
In this sort of embodiment, device 22 may create a 3D map of a given object using the IR pattern, and may then project onto the object a visible image that is tailored to the shape and contours of the object. This sort of capability is useful, for example, in presenting user interface graphics and text, and particularly in “augmented reality” applications (for which device 22 may even be integrated into goggles worn by the user so that mapping and visible image projection are aligned with the user's field of view). Applications of this sort are described, for example, in PCT Patent Application PCT/IB2011/053192, filed Jul. 18, 2011, whose disclosure is incorporated herein by reference.
As shown in
As mirror 50 scans over FOV 36, processor 46 modulates sources 32 and 72 simultaneously: Source 32 is modulated to generate the desired pattern for 3D mapping at each point in the field, while source 112 is modulated according to the pixel value (intensity and possibly color) of the visible image that is to be projected at the same point (which may be based on the 3D map of the object at that point). Because the visible and IR beams are optically aligned and coaxial, the visible image will be automatically registered with the 3D map.
Objective optics 42 comprise an astigmatic imaging element, which maps field of view 44 onto image sensor 120. Optics 42 have larger magnification in the Y-direction than in the X-direction, so that each row 122 of the image sensor captures light from a corresponding rectangular area 124 in the field of view. For example, the aspect ratio of each rectangular area 124 may be on the order of 10:1 (X:Y), while rows 122 have an aspect ratio on the order of 1000:1. The different X- and Y-magnifications of optics 42 may be chosen in any desired ratio, depending on the number of rows and columns in the image sensor and the desired dimensions of the field of view. In one embodiment, for example, optics 42 may comprise a cylindrical lens, and sensor 120 may comprise only a single row of detector elements.
Illumination module 30 scans the beam from radiation source 32 over field of view 44 in a raster pattern, covering each of areas 124 with multiple horizontal scan lines. As each line in a given area 124 is scanned by the spot from the illumination module, the corresponding row 122 captures the radiation reflected from the scene. Readout from sensor 120 is synchronized with the illumination scan, so that the rows 122 of detector elements 41 are read out substantially only when the corresponding areas 124 in the scene are illuminated by the scan. As a result, the length of time during which each row 122 integrates ambient light for each readout is reduced, and the signal/ambient ratio in the output of sensor 120 is thus enhanced.
The resolution of the images captured by module 38 in this embodiment is governed by the resolution of the illumination scan, as each row 122 of sensor 120 is read out multiple times in synchronization with the scan. In other words, the first row is scanned multiple times while illumination module scans the corresponding area 124, followed by multiple scans of the second line, then the third line, etc. For example, if the first row in the image sensor is responsible for capturing the first hundred scan lines of the illumination module ( 1/10 of the vertical FOV), then it is scanned one hundred times before the second line is scanned. For this purpose, sensor 120 includes suitable readout circuits (not shown), similar to the readout circuits in a conventional, full-resolution CMOS image sensor, for example. Alternatively, a vertical fan-out element may be used on the illumination side, and the lines of the image sensor may scan simultaneously, each synchronized with the corresponding illumination scan.
Alternatively, the scanning of image sensor 120 may be vertically multiplexed in synchronization with the illumination scan. In this scheme, for example, using an imaging sensor with one hundred rows, the first row of the image sensor captures, for example, the first, 101st, 201st, 301st scan line, etc., of the illumination scan. Additionally or alternatively, imaging module 38 may implement the sort of spatially-multiplexed imaging schemes that are described, for example, in U.S. Provisional Patent Application 61/419,891, filed Dec. 6, 2010, whose disclosure is incorporated herein by reference. A combination of the above scanning techniques can also be used.
The arrangement of image capture module 38 that is shown in
In the embodiment of
In the pictured embodiment, objective optics 42 map a rectangular area 134 in field of view 44 onto the row of detector elements 41 in sensor 130. Optics 42 may, as in the preceding embodiment, be astigmatic, with greater optical power in the X-direction than in the Y-direction, so that area 134 has a lower aspect ratio (X:Y) than the row of detector elements in the sensor. A scanning mirror 132 scans area 134 over field of view 44 in the Y-direction, in synchronization with the raster scan of illumination module 30, so that area 134 always contains the horizontal line that is currently under patterned illumination. In this manner, the image capture module captures an image of the pattern on the scene with high resolution and high signal/ambient ratio, while using a simple one-dimensional sensor.
The sensing area of imaging module 144 is thus scanned over the region of interest in synchronization with the scanned beam of illumination module 142. Detector 154 may comprise, for example, a position-sensitive detector as in the embodiment of
The arrangement shown in
A number of specific ways to enhance scanning architectures for pattern projection and image capture have been shown and described above. These embodiments illustrate, by way of example, how aspects of the present invention can be used, inter alia, to improve eye safety, to increase field of view, to simultaneously use the same scanning hardware to project both IR patterns and visible content, and to reduce the size of the imaging module by synchronizing it with the illumination module. Alternative implementations and combinations of the above embodiments are also considered to be within the scope of the present invention. Such schemes may use various combinations of scanning projection for 3D mapping, as well as projection of visible information; diffractive optics to shape or split the scanning beam; refractive and/or diffractive optics to enlarge the field of view of the projection system; and synchronized scanning of projection and image capture.
It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
Pesach, Benny, Shpunt, Alexander, Akerman, Ronen
Patent | Priority | Assignee | Title |
10721459, | Aug 11 2010 | Apple Inc. | Scanning projectors and image capture modules for 3D mapping |
Patent | Priority | Assignee | Title |
4713544, | Mar 05 1984 | Siemens Aktiengesellschaft | Optical system for the simultaneous reception of thermal and laser radiation |
7949024, | Feb 17 2009 | Lumentum Operations LLC | Multibeam arrays of optoelectronic devices for high frequency operation |
9098931, | Aug 11 2010 | Apple Inc | Scanning projectors and image capture modules for 3D mapping |
9677878, | Aug 11 2010 | Apple Inc. | Scanning projectors and image capture modules for 3D mapping |
20050046850, | |||
20070223329, | |||
20110106324, | |||
20110292406, | |||
20130107000, | |||
JP2000348367, | |||
JP2001249254, | |||
JP2002026452, | |||
JP2006310417, | |||
JP2007235439, | |||
JP4102239, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Jan 06 2013 | SHPUNT, ALEXANDER | Primesense Ltd | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 042269 | /0112 | |
Jan 09 2013 | PESACH, BENNY | Primesense Ltd | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 042269 | /0112 | |
Jan 10 2013 | AKERMAN, RONEN | Primesense Ltd | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 042269 | /0112 | |
Aug 28 2014 | Primesense Ltd | Apple Inc | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 042269 | /0129 | |
May 08 2017 | Apple Inc. | (assignment on the face of the patent) | / |
Date | Maintenance Fee Events |
Aug 10 2022 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Date | Maintenance Schedule |
Feb 26 2022 | 4 years fee payment window open |
Aug 26 2022 | 6 months grace period start (w surcharge) |
Feb 26 2023 | patent expiry (for year 4) |
Feb 26 2025 | 2 years to revive unintentionally abandoned end. (for year 4) |
Feb 26 2026 | 8 years fee payment window open |
Aug 26 2026 | 6 months grace period start (w surcharge) |
Feb 26 2027 | patent expiry (for year 8) |
Feb 26 2029 | 2 years to revive unintentionally abandoned end. (for year 8) |
Feb 26 2030 | 12 years fee payment window open |
Aug 26 2030 | 6 months grace period start (w surcharge) |
Feb 26 2031 | patent expiry (for year 12) |
Feb 26 2033 | 2 years to revive unintentionally abandoned end. (for year 12) |